It has been proposed in European Patent Publication No. 0 095 933 (Palmaer) to include a downwardly projecting guide member 32, as shown in FIGS. 7 and 8, which engages a track or guide to resist side loading when a belt follows a curved path. However, no provision is made for any resistance to upwards movement of the conveyor which tends to occur of the outermost part of the conveyor with respect to the turn.